JComboBox


1   /*
2      SwingWT
3      Copyright(c)2003-2004, R. Rawson-Tetley
4   
5      For more information on distributing and using this program, please
6      see the accompanying "COPYING" file.
7   
8      Contact me by electronic mail: bobintetley@users.sourceforge.net
9   
10     $Log: JComboBox.java,v $
11     Revision 1.36  2004/05/06 00:28:22  laurentmartelli
12      - setSelectedIndex() calls model.setSelectedItem()
13      - handleComboKeyStrokes() does not raise NullPointerException if litems==null
14  
15     Revision 1.35  2004/05/05 17:19:39  bobintetley
16     Fix to make JComboBox update the selected item on it's model as the user
17     chooses another item. Removed debug code from Everything demo
18  
19     Revision 1.34  2004/05/05 16:46:53  bobintetley
20     JTree rendering fix for collapse/expansion
21  
22     Revision 1.33  2004/05/05 16:11:34  bobintetley
23     (Laurent Martelli) JComboBox performance patch
24  
25     Revision 1.32  2004/05/05 12:43:21  bobintetley
26     Patches/new files from Laurent Martell
27  
28     Revision 1.31  2004/04/30 23:18:26  dannaab
29     List selection support, misc bug fixes
30  
31     Revision 1.30  2004/04/28 08:38:11  bobintetley
32     Hierarchy fixes, code cleanup for base classes, additional javadocs and use of flag to identify JComponent descendants with peers
33  
34     Revision 1.29  2004/04/19 10:49:37  bobintetley
35     Fix to cell editing with DefaultEditor/JComboBox and fix so JTable/JTree
36     cell renderers are used after editor updates
37  
38     Revision 1.28  2004/04/16 14:38:47  bobintetley
39     Table and Tree cell editor support
40  
41     Revision 1.27  2004/04/16 10:19:06  dannaab
42     Misc bug fixes, InputMap implementation, preliminary undo support
43  
44     Revision 1.26  2004/03/30 10:42:46  bobintetley
45     Many minor bug fixes, event improvements by Dan Naab. Full swing.Icon support
46  
47     Revision 1.25  2004/02/20 13:57:01  bobintetley
48     JLookupPopup - A high speed alternative to JComboBox
49  
50     Revision 1.24  2004/02/13 15:09:23  bobintetley
51     JComboBox/Abstract button non-peer selection and JTable threading fixed
52  
53     Revision 1.23  2004/02/03 09:21:21  bobintetley
54     Fixed threading bug in invokeIn, and JComboBox hotkeys
55  
56     Revision 1.22  2004/01/26 09:10:09  bobintetley
57     JComboBox event fixes, fix to Java2D garbage collection and ComboBox demo
58  
59     Revision 1.21  2004/01/23 08:04:56  bobintetley
60     JComboBox fixes and better Action implementation
61  
62     Revision 1.20  2004/01/16 10:07:28  bobintetley
63     ItemEvent/Listener support for combo
64  
65     Revision 1.19  2004/01/08 12:56:30  bobintetley
66     Experiment with hotkeys - unworkable in current SWT
67  
68     Revision 1.18  2004/01/04 12:02:41  bobintetley
69     Fix to broken popupMenu events, default values and null data handling
70  
71     Revision 1.17  2003/12/17 09:03:14  bobintetley
72     Closely matches Swing behaviour + JScrollPane support for Panels
73  
74     Revision 1.16  2003/12/16 17:46:17  bobintetley
75     Additional thread safety methods
76  
77     Revision 1.15  2003/12/16 15:47:45  bobintetley
78     Thread safety added to common methods
79  
80     Revision 1.14  2003/12/16 13:14:33  bobintetley
81     Use of SwingWTUtils.isSWTControlAvailable instead of null test
82  
83     Revision 1.13  2003/12/16 11:01:02  bobintetley
84     Additional Swing compatibility
85  
86     Revision 1.12  2003/12/15 18:29:57  bobintetley
87     Changed setParent() method to setSwingWTParent() to avoid conflicts with applications
88  
89     Revision 1.11  2003/12/15 17:37:18  bobintetley
90     ComboBox model interfaces and support
91  
92     Revision 1.10  2003/12/15 15:53:55  bobintetley
93     maximumRowCount()
94  
95     Revision 1.9  2003/12/14 09:13:38  bobintetley
96     Added CVS log to source headers
97  
98  */
99  
100 
101 package swingwtx.swing;
102 
103 import swingwtx.swing.event.*;
104 import swingwt.awt.event.*;
105 
106 import org.eclipse.swt.events.*;
107 import org.eclipse.swt.widgets.*;
108 import org.eclipse.swt.*;
109 
110 import java.util.*;
111 
112 public class JComboBox extends swingwtx.swing.JComponent {
113 
114     protected Combo ppeer = null;
115     protected String   pText = "";
116     protected Vector litems = null;
117     protected int pSelectedIndex = -1;
118     protected int pMaxRows = 8;
119     protected Vector popupListeners = new Vector();
120     protected Vector itemListeners = new Vector();
121     protected Vector changeListeners = new Vector();
122     protected ComboBoxModel model = null;
123 
124     /** Used for thread safe property accessor calls */
125     private Object   retValue = null;
126 
127     /** Used to determine if the combo can be entered into */
128     protected boolean isEditable = false;
129 
130     public JComboBox() { litems = new Vector(); }
131 
132     public JComboBox(Object  [] items) {
133         litems = new Vector();
134         for (int i = 0; i < items.length; i++) {
135             litems.add(items[i]);
136         }
137         if (!isEditable && litems.size() > 0)
138             pSelectedIndex = 0;
139     }
140 
141     public JComboBox(Vector items) {
142         litems = items;
143         if (!isEditable && litems != null && litems.size() > 0)
144             pSelectedIndex = 0;
145     }
146 
147     public JComboBox(ComboBoxModel model) {
148         this.model = model;
149         copyModel();
150         if (!isEditable && litems != null && litems.size() > 0)
151             pSelectedIndex = 0;
152     }
153 
154     protected final static int CANCELED = 0;
155     protected final static int INVISIBLE = 1;
156     protected final static int VISIBLE = 2;
157     
158     public void addChangeListener(ChangeListener l) {
159         changeListeners.add(l);    
160     }
161     
162     public void removeChangeListener(ChangeListener l) {
163         changeListeners.remove(l);    
164     }
165     
166     public void addPopupMenuListener(PopupMenuListener l) {
167         popupListeners.add(l);
168     }
169 
170     public void removePopupMenuListener(PopupMenuListener l) {
171         popupListeners.remove(l);
172     }
173 
174     public void addItemListener(ItemListener l) {
175         itemListeners.add(l);
176     }
177 
178     public void removeItemListener(ItemListener l) {
179         itemListeners.remove(l);
180     }
181 
182     public void processPopupMenuEvent(int id) {
183         Iterator i = popupListeners.iterator();
184         PopupMenuEvent e = new PopupMenuEvent(this);
185         while (i.hasNext()) {
186             PopupMenuListener l = (PopupMenuListener) i.next();
187             switch(id) {
188                 case CANCELED: l.popupMenuCanceled(e); break;
189                 case INVISIBLE: l.popupMenuWillBecomeInvisible(e); break;
190                 case VISIBLE: l.popupMenuWillBecomeVisible(e); break;
191             }
192         }
193     }
194 
195     public void processItemEvent(ItemEvent e) {
196         
197     // The model needs to be informed of the new selection
198     if (model != null)
199         model.setSelectedItem(e.getItem());
200             
201         for (int i = 0; i < itemListeners.size(); i++) {
202             ItemListener l = (ItemListener) itemListeners.get(i);
203             l.itemStateChanged(e);
204         }
205     }
206 
207     public void processChangeEvent(ChangeEvent e) {
208         for (int i = 0; i < changeListeners.size(); i++) {
209             ChangeListener l = (ChangeListener) changeListeners.get(i);
210             l.stateChanged(e);
211         }
212     }
213     
214 
215     /** Handles copying of Combo box models so they can be
216      *  handled by SWT
217      */
218     protected void copyModel() {
219         if (model == null) return;
220         litems = new Vector(model.getSize());
221         for (int i = 0; i < model.getSize(); i++) {
222             litems.add(model.getElementAt(i));
223         }
224     }
225 
226     public Object   getSelectedItem() {
227         retValue = null;
228         SwingUtilities.invokeSync(new Runnable  () { public void run() {
229             if (isEditable) {
230                 if (!SwingWTUtils.isSWTControlAvailable(ppeer))
231                     retValue = pText;
232                 else
233                     retValue = ppeer.getText();
234             }
235             else {
236                 if ((!SwingWTUtils.isSWTControlAvailable(ppeer)) && pSelectedIndex > -1)
237                     retValue = litems.get(pSelectedIndex);
238                 else if (SwingWTUtils.isSWTControlAvailable(ppeer))
239                     if (ppeer.getSelectionIndex() != -1)
240                         retValue = litems.get(ppeer.getSelectionIndex());
241             }
242         }});
243         return retValue;
244     }
245 
246     public void setSelectedItem(final Object   text) {
247         SwingUtilities.invokeSync(new Runnable  () {
248             public void run() {
249                 if (isEditable) {
250                     if (!SwingWTUtils.isSWTControlAvailable(ppeer))
251                         pText = text.toString();
252                     else
253                         ppeer.setText(text.toString());
254                 }
255                 else {
256                     // If we are dealing with a String, use a string comparison
257             if (litems != null) {
258                         if (text instanceof String  ) {
259                             Object  [] itm = litems.toArray();
260                             for (int i = 0; i < itm.length; i++)
261                                  if (itm[i].toString().equals(text.toString())) {
262                                     setSelectedIndex(i);
263                                     break;
264                                 }
265                         }
266                         else {
267                             // Object comparison
268                             int index = litems.indexOf(text);
269                             if (index != -1) setSelectedIndex(index);
270                         }
271             }
272                 }
273             }
274         });
275     }
276 
277     public ComboBoxModel getModel() { return model; }
278     public void setModel(ComboBoxModel model) {
279         this.model = model;
280         copyModel();
281         if (SwingWTUtils.isSWTControlAvailable(ppeer)) {
282         String  [] items = new String  [litems.size()];
283         for (int i=0; i < litems.size(); i++) {
284         Object   o = litems.get(i);
285         items[i] = o == null ? "" : o.toString();
286         }
287         ppeer.setItems(items);
288         }
289     }
290 
291     public void addItem(final Object   item) {
292         if (litems == null)
293             litems = new Vector();
294         litems.add(item);
295 
296         SwingUtilities.invokeSync(new Runnable  () {
297             public void run() {
298                 if (SwingWTUtils.isSWTControlAvailable(ppeer))
299                     ppeer.add(item.toString());
300             }
301         });
302 
303     }
304 
305     public void insertItemAt(final Object   item, final int index) {
306         if (litems == null)
307             litems = new Vector();
308         litems.add(index, item);
309         SwingUtilities.invokeSync(new Runnable  () {
310             public void run() {
311                 if (SwingWTUtils.isSWTControlAvailable(ppeer))
312                     ppeer.add(item.toString(), index);
313             }
314         });
315     }
316 
317     public int getSelectedIndex() {
318         retValue = null;
319         SwingUtilities.invokeSync(new Runnable  () {
320             public void run() {
321                 if (!SwingWTUtils.isSWTControlAvailable(ppeer))
322                     retValue = new Integer  (pSelectedIndex);
323                 else
324                     retValue = new Integer  (ppeer.getSelectionIndex());
325             }
326         });
327         return ((Integer  ) retValue).intValue();
328     }
329 
330     public Object   getItemAt(int index) {
331         if (index == -1)
332             return null;
333         return litems.get(index);
334     }
335     
336     public swingwt.awt.Component getComponent(int n) {
337         return this;
338     }
339 
340     public int getItemCount() {
341         return litems.size();
342     }
343 
344     public void setSelectedIndex(final int index) {
345         final JComboBox me = this;
346         if (model!=null) {
347             if (index!=-1)
348                 model.setSelectedItem(model.getElementAt(index));
349             else
350                 model.setSelectedItem(null);
351         }
352         SwingUtilities.invokeSync(new Runnable  () {
353             public void run() {
354                 if (!SwingWTUtils.isSWTControlAvailable(ppeer))
355                     pSelectedIndex = index;
356                 else {
357                     ppeer.select(index);
358                     processActionEvent(0);
359                     ItemEvent ie = new ItemEvent(me, 0, getSelectedItem(), ItemEvent.SELECTED);
360                     processItemEvent(ie);
361                 }
362             }
363         });
364     }
365 
366     public void removeAllItems() {
367         if (litems != null)
368             litems.removeAllElements();
369         SwingUtilities.invokeSync(new Runnable  () {
370             public void run() {
371                 if (SwingWTUtils.isSWTControlAvailable(ppeer))
372                     ppeer.removeAll();
373             }
374         });
375     }
376 
377     public void removeItem(final Object   item) {
378         litems.remove(item);
379         SwingUtilities.invokeSync(new Runnable  () {
380             public void run() {
381                 if (SwingWTUtils.isSWTControlAvailable(ppeer))
382                     ppeer.remove(item.toString());
383             }
384         });
385     }
386 
387     public void removeItemAt(final int index) {
388         litems.remove(index);
389         SwingUtilities.invokeSync(new Runnable  () {
390             public void run() {
391                 if (SwingWTUtils.isSWTControlAvailable(ppeer))
392                     ppeer.remove(index);
393             }
394         });
395     }
396 
397     public void setEditable(boolean b) {
398         isEditable = b;
399     }
400 
401     public boolean getEditable() {
402         return isEditable;
403     }
404 
405     public int getMaximumRowCount() {
406         return pMaxRows;
407     }
408     public void setMaximumRowCount(int max) {
409         pMaxRows = max;
410     }
411 
412     /**
413      * Once a parent component receives an "add" call for a child, this being
414      * the child, this should be called to tell us to instantiate the peer
415      * and load in any cached properties.
416      */
417     public void setSwingWTParent(swingwt.awt.Container parent) throws Exception   {
418         descendantHasPeer = true;
419         ppeer = new Combo(parent.getComposite(), SWT.BORDER | SWT.DROP_DOWN );
420         
421         if (litems != null) {
422         String  [] items = new String  [litems.size()];
423         for (int i=0; i < litems.size(); i++) {
424         Object   o = litems.get(i);
425         items[i] = o == null ? "" : o.toString();
426         }
427         ppeer.setItems(items);
428         }
429         
430         if (pSelectedIndex != -1)
431             ppeer.select(pSelectedIndex);
432 
433             // Real Swing combos default to the first item if none are selected
434         else if (litems != null && litems.size() > 0) {
435             pSelectedIndex = 0;
436             ppeer.select(0);
437         }
438         // If the combo is editable, default the text supplied if we have some
439         if (isEditable)
440             if (!pText.equals(""))
441                 ppeer.setText(pText);
442 
443         peer = ppeer;
444         this.parent = parent;
445 
446         registerComboEvents();
447     }
448 
449     protected void registerComboEvents() {
450 
451         final JComboBox me = this;
452 
453         // Popup menu event mapped listener
454         ppeer.addModifyListener(new ModifyListener() {
455             public void modifyText(ModifyEvent e) {
456                 // Only fire when the text is changed
457                 if (ppeer.getSelectionIndex() != -1) {
458                     processPopupMenuEvent(INVISIBLE);
459                     processPopupMenuEvent(VISIBLE);
460                     processPopupMenuEvent(CANCELED);
461                 }
462             }
463         });
464 
465         // Selection changed
466         ppeer.addSelectionListener(new SelectionAdapter() {
467             public void widgetSelected(SelectionEvent e) {
468                 ItemEvent ie = new ItemEvent(me, 0, getSelectedItem(), ItemEvent.SELECTED);
469                 processItemEvent(ie);
470                 ChangeEvent ce = new ChangeEvent(me);
471                 processChangeEvent(ce);
472                 processActionEvent(0); // Fire an action event when selection changes
473             }
474         });
475 
476         // Changing selection on key strokes for non-editable combos
477         handleComboKeyStrokes();
478 
479     }
480 
481     /**
482      * This routine will add the key handlers necessary for searching
483      * through combos by the key pressed (as Windows does, and as Swing does).
484      *
485      * This code really isn't too pretty, as SWT deactivates the key events if
486      * SWT.READ_ONLY is specified, so I have to handle that too, also you
487      * can't consume KeyEvents under a Combo (must be a bug), so I use a timer
488      * over the event pump to reset values. As I say, it's dirty but it works.
489      *
490      * @author Robin Rawson-Tetley
491      */
492     protected void handleComboKeyStrokes() {
493 
494         // If the combo isn't editable, then set up hot keys to search the list
495         // when the user presses a key. I can't BELIEVE I have to frigging code this
496         // and SWT doesn't do this anyway!
497 
498         if (isEditable) return;
499 
500         ppeer.addKeyListener(new org.eclipse.swt.events.KeyAdapter() {
501             public void keyPressed(org.eclipse.swt.events.KeyEvent e) {
502 
503                 // Cancel the keystroke -- maybe one day it will work...
504                 e.doit = false;
505 
506                 // If ALT or CTRL is pressed, ignore this code.
507                 if ( ((e.stateMask & SWT.ALT) > 0) ||
508                      ((e.stateMask & SWT.CTRL) > 0) ) return;
509 
510                 // See what's already selected - this way we can cycle
511                 // up the list like Swing does.
512                 int currentlySelected = getSelectedIndex();
513 
514                 // The current character we are dealing with
515                 String   curChar = "";
516         String   selected = "";
517         
518                 if (currentlySelected != -1)
519             selected = getSelectedItem().toString();
520         
521                 if (currentlySelected != -1 && selected.length() > 0)
522                     curChar = selected.substring(0, 1).toLowerCase();
523 
524                 boolean foundMatch = false;
525 
526                 if (litems!=null) {
527                     for (int i = 0; i < litems.size(); i++) {
528                         String   s = litems.get(i).toString();
529                         // This item start with the same letter?
530                         if ( s.length() > 0 &&
531                              s.substring(0, 1).toLowerCase().equals(new String  (new char[] { e.character }).toLowerCase()) )
532                         {
533 
534                             // Was the last keystroke on this letter? If so, the index must be higher
535                             if (curChar.equals(new String  (new char[] { e.character }).toLowerCase()))
536                                 i = currentlySelected + 1;
537 
538                             // If we've run out of letters, don't do anything
539                             if (i >= litems.size())
540                                 break;
541 
542                             // Now that we've moved the match up, make sure the letters still
543                             // match - if they don't, then we've gone too far - don't do
544                             // anything
545                             if (!litems.get(i).toString().substring(0, 1).toLowerCase().equals(new String  (new char[] { e.character }).toLowerCase()))
546                                 break;
547 
548                             foundMatch = true;
549 
550                             // Because we can't cancel the keystroke, we let it
551                             // go and then change the value again afterwards - thanks SWT!
552                             final int matchedIndex = i;
553                             SwingUtilities.invokeIn(new Runnable  () {
554                                     public void run() {
555                                         setSelectedItem(litems.get(matchedIndex));
556                                     }
557                                 }, 1);
558                             break;
559 
560                         }
561                     }
562                 }
563 
564                 // We didn't find one, reassert the current value to overwrite
565                 // the keystroke.
566                 if (!foundMatch) {
567                     final Object   selItem = getSelectedItem();
568                     SwingUtilities.invokeIn(new Runnable  () {
569                         public void run() {
570                             setSelectedItem(selItem);
571                         }
572                     }, 1);
573                 }
574 
575             }
576         });
577 
578     }
579 
580 }
581
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